Sewing machine



Nov. 2 1926.

- R. OLIVER sawme MACHINE Filed Oct. '12, 1925 3 Sheets-sheaf 1'.

I l'n'venTor. John Roger Oliver b is? .N. WI y W Wild, i xTys Nov. 2 1926 J. R. OLIVER SEWING MACHINE Filed Oct. 12 1925 3 Sheets-Sheet. 2

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, Nov. 2 1926.

0 1,605,060 r J. R. OLIVER SEWING MACHINE I Filed Oct. 12, 1925 3 Sheets-Sheet 3 lnQer Tor. John RogerQllver b \n y, gga-Y Patented Nov. 2, 19.26.

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JOHN ROGER OLIVER, OF. MEDFIELD, MASSACH'UFSETTS, .ASSIGNOR REECE SHOE IVIACHINEBY COMFANY, 015 BOSTON, MASSACHUSETTS, A CGRPORATION OIE MAINE.

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Application filed October 12, 1925. Serial No. 62,025.

as the weltand-turn machine, represented for example by Patents 1,288,366 ofDecember 17, 1918, and 1,361,952 of December 1 1, 1920, and certain pending applications of mine, although the novel features of the present invention are applicable to other types of shoe stitching machines or other sewing machines. The general object of the present invention is to improve the operation and eliiciency of the thread tension control mechanism of a sewingmachine of the kinds referred to. A specific object is to provide automatic means for causing the relaxing of the tension upon the wax thread or other thread at one or more points in the stitch cycle in an effective and accurate manner and with smoothness and tion. A. further object is to provide a simple mechanism for such purpose, and one which can be readily adjusted as to the timing of the points of release or relaxation of the tension device. Further objects and advantages of the present invention will be explained in the hereinafter following description of an illustrative embodiment thereof, or will be apparent to those skilled in the art. To the attainment of the objects and advantages referred tothe present invention consists in the novel sewing machine and the novel features of combination, arrangement and structure herein illustrated or described. In the accompanying,drawings F ig. 1 1s a right hand elevation showing suflicient 0f the exterior parts of the machine to afford an explanation of the present invention.

Fig. 2 is an opposite or left hand elevation of the same, taken partly in section on the line 22 of Fig. 3. V

Fig. 3 is a top plan view showing the main elements particularly concerned with the present invention.

Fig. 4 is a front parts.

Fig. 5 is a front elevation of one of the operating eccentrics, detached from the machine.

Fig. 6 is a section on the line 66 of Fig. 5.

Fig. 7 is a top plan view and section taken on the line 7 of Fig. 4:.

elevation of the same quietness of opera- Fig. 8 is a detail section taken on the line 8-8 of ig. 7. a

The cycle of stitching operations in a welt: and-turn stitching machine may be substantially as indicated in the diagram in said Patent 1,288,366 which shows the movements'of the needle, the looper, the thread hook, the takeup, the work feed means, etc.

I find it desirable to relax or release the thread tension at two different points in the cycle, namely first during the measuring of thread, which consists in pulling thread from the supply at a time when the needle is forward and the looper, take-up and thread hook are working in cooperation therewith, and at the point in the cycle when the work is being fed forwardly, which may be a point substantially opposite to the thread measuring point of the cycle. The action at these two points may consist in a relaxing of the resistance or tension upon the thread, or a substantial release of tension, or

in the case of thread of inferior quality an entire removal of tension. No claim is made herein broadly to the varying of the tension on the thread of a welt-and-turn stitching machine, but so far as I am aware the prevailing practise has been to employ a cam for this purpose, resulting in an abrupt or unsatisfactory action, producing noise, and not affording the desirable adjustment of timing already mentioned. With the pres ent invention a novelmeohanism is shown wherein a pair of eccentrics operate in a smooth manner, independently of each'other, to effect the relaxation or release of tension at the desired points in the stitch cycle, with means for'securing adjustment and the other advantages referred to. V

In the drawings the vertical frame wall 11 may be the right hand one of the two vertical frame walls shown in the prior patents and applications referred to. T he main or stitching shaft 12 has suitable connections to the needle and other instrumcntalities, such connections including for example a crank 13 formed on the shaft 12. The shaft is journalled in a'bcaring 1 1 in the frame wall 11 and may be similarly journalled at its other end.

Among the other illustrated fixed parts of the machine is shown a bearing stud 15 supported in part by a post 16. this stud extending to the right of the post as indicated.

upon the wheel and thread' A pressuredisk 19 is engaged against the outer felt disk 18 and may be guided by the extremity of the fixed stud 15. The pressure dlsk has a shank 20 extending through the frame wall 11 and provided at its exterior end with a head or forked enlargement 2.1. Surrounding the shank 20is shown a threaded sleeve 22 which engages in threads cut in the frame wall 11 and is provided with a head 23 by which the sleeve may be turned to adjust the normal degree of tension or pressure. The shank 20 runs freely through the adjusting sleeve 22 and is surrounded by a pressure spring 24 which bears against the threaded sleeve at one end and against the pressure disk 19 at the other end, thus norn ally imposing the maximum tension upon the thread wheel and thread. In connection with such tension mechanism this invention comprises means, as will be described, by which .a reduction is effected of the pressure of the disk 19 upon the thread wheel. The tension may be thus relaxed by a hand lever 25 shown in Fig. 1 which is universally pivoted and the lower end of which may be swung toward the frame wall to cause the upper end to thrust outwardly upon the head 21 of the shank of the pressure disk. The present invention however relates more particularly to automatically timed relaxing of tension as will now be described.

The automatic control of the tension is through a rock lever 26 which swings on a horizontal pivot pin 27 mounted in a bear ing lug 28 at the right side of the fram wall, the rock lever having a forked extension 29 embracing the shank 20 of the pressure disk and bearingagainst the head 21 of the shank. hen the rock lover is swung outwardly the extension 25) presses against.-

the head 21 and relaxes the tension.

The swinging movements of the rock lever 26 may be effected through the following mechanism. The lever is shown having two upstanding ears 3 and 31 through which is engaged a. pin 32 adapted to be pushed or pressed against for swinging the rock lever. The degree of movement or swing may be regulated by eccentric adjust ment of the push pin and it is shown as having a threaded head 33 and a sliding head arranged in alinement with each other but concentric with the central part of the pin 32. The threaded head 33 engages with threads in the front ear and the push pin can be turned by means of nick 1 35 at its outer extremity, thus changing the position of the central part of the pin in relation to the lever. A. lock nut 36 serves to secure the parts in adjusted position.

The pushing outward or to the right of the rock lever 26 is effected, as stated, by pressing upon the push pin 82. The actual. swinging movement to effect the desired relaxation of the tension may be very slight, as short even as 1/64th of an nch, sufiicient to relax or release the tension for the purposes stated. As it is desired to relax the tension at two points in the cycle there are shown two separate swinging or pushing means in the form of push rods 37 at the front and 38 to the rear of it, these being slotted rods, the slots engaging about the push pin 32. These two rods are operated alternately by means oftwo constantly rotating eccentrics as will nergt be described.

The operating means for swinging the rock lever and thereby relaxing the tension may be driven from a helical gear 39 on the stitching shaft 12 engaging a helical gear 40 arranged on a shaft 41 set at right angles to the shaft 12 and above it; the ratio of the gears being one to one so that the 40 makes one rotation for each rotation of the shaft 12. The shaft 41 is journalled in fixed lugs or brackets 42 and 43 located at the inher side of the frame wall. The gear 40 carries at its front side an eccentric 44 and at its rear side an eccentric 45. The eccentric 44 is surrounded. by a strap 46 attached at the inner end of the front push rod 3'4", while the eccentric is surrounded by a strap 47 connected. with the push rod By this arrangement the eccentrics. according to their timing, thrust the ish rods 3? and 38 alternately to the right. the push rods acting on the push pin 32 and thereby swing ing the rock lever and relaxing the tension as follows. Fig. 5 showing either a front view of eccentric 45 or a rear view of eccentrio 44. The throw of the eccentric is not herein adjusted, as the effective throw can be controlled by the adjustment of the push pin 32 as described. Each eccentric is bored with a hole 48 fitting over the shaft 41. The hole 48 is eccentrically arranged, permitting the eccentric to be swung around to various posi tions. An elongated slot 49 is arranged in the eccentric. concentric with the opening 48. and a threaded stud or screw 50 is inserted through this slot and enga (red in one or the other of a number of threaded holes 51 formed in the face of the gear 40 surrounding the central shaft. Thus six stud holes 51 are shown, each adapted to receive the stud or screw 50, thus giving six different positions of the stud. In connection with such positioning of the stud the elongated slot 49 allows substantial swinging adjustment of the eccentric in each stud position. Thereby the eccentric can be set and secured in any desired position. By reason of this the gears and other parts may be first assembled and the eccentrics then set and timed to give the tension relaxation at the proper points in the stitch cycle.

The drawings, Figs. 3, 4 and 7, show the parts in a position in which the eccentric 45, operating through the strap 47 and push rod 38 is operating against the push pin 32 and thus releasing the tension, this being at the thread measuring point in the stitching cycle, thus preventing the breakage of thread. T he smooth motion afforded by the eccentric gives a very quiet and accurate operation. A crank might in some cases be used to give a similar motion and may therefore broadly be considered as included in the term eccentric. Theshank 20 and its head 21 may be considered as a tension releasing member, this being operated by the swinging lever 26 when the tension is to be released. By releasing it is intended to cover either a relaxing to decrease the resistance on the thread or a complete removing of resistance. The tension releasing member may be considered as normally inactive, the tension spring 24 normally operating to apply full resistance to the thread. The operation of each of the eccentrics hereof is to actuate the releasing member or shank 20 and this is done by an easy bumping or tapping action at the extreme position of the eccentric throw. The slotted rods 37 and 38 give loose play and it is only at their furthest position of throw that they contact and bump the rock lever 26 thus giving it a short swing, which is accurately timed, but is easy and slow, due to the fact that the eccentric is at the end of its throw. The lever transmits this motion, as explained, to the tension releasing rod or shank 20 and thereby to the presser or disk 19, which is thus given aqnick retraction. At approximately 180 of rotation of the shafts 12 and 41 the other eccentric 44 will come into playto bump the push pin 32 and thereby release the tension, namely at the point in the cycle during which the work is being fed, this point also corresponding substantially, in a welt-andturn sewing machine, with the final stop position of the parts.

It will thus be seen that there has been described a sewing machine of the type referred to disclosing the features and attaining the objects of the present invention; but as many matters, of arrangement, combination, design and detail may be variously modified without departing from the principles of the invention it is not intended to limit the invention to such matters except in so far as specified in the appended claims.

hat is claimed is:

1. In a sewing machine an operating shaft for driving the stitching means, a thread tension device normally applying resistance to the drawing of thread, and two independent eccentrics, differently timed, one operating to release the tension at the thread measuring point and the other at the work feeding point in the stitch cycle, said eccentrics rotated from said operating shaft.

2. In a shoe stitching or analogous machine, a thread wheel, a presser applying friction thereto, spring means normally pressing the presser into operative position, and means working in time with the stitch cycle for retracting said presser to relax or remove the tension on the thread at a predetermined point in the cycle comprising an eccentric turning continuously in time with the stitching, and loose connections from the eccentric to the presser, such that during the greater part of the eccentrics movement the connections are inoperative and become operative only at the end of the movement to give a quick retraction of the presser.

A machine as in claim 2 and wherein the loose connections from the eccentric to the presser comprise a rock lever in permanent connection with the presser, said rock lever having a contact member eccentrically mounted, means for adjusting same to vary the extent of swing of the lever, and a pusher member in permanent connection with the.

a helical gear, a helical gear engaging saidgear, with ratio one to one, and said two eccentrics mounted at opposite sides of said second gear.

6. In a power sewing machine a thread tension device normally in operation comprising resilient pressure means, and means automatically relaxing the tension at two points in the stitch cycle comprising two eccentrics both turning continuously in time with the stitching and connections operated alternately by the eccentrics to relax the tension.

In testimony whereof, I have aflixed my signature hereto.

JOHN ROGER OLIVER. 

